Shia recently admitted the cast have signed up for engaging in real sex scenes on camera, which he is willing to do for the sake of his art.

He said: ''There's a disclaimer at the top of the script that basically says we're doing it for real. Everything that is illegal, we'll shoot in blurred images. Other than that, everything is happening.''

Speaking of Trier, he added: ''He's very dangerous. He's the most dangerous dude I've ever showed up for. I'm terrified.''

The film will be available in two versions - hardcore and softcore - when it is released in 2013.